1. Field of the Invention
The present invention relates to an image pickup apparatus, an image pickup method, and a computer program product.
2. Description of the Related Art
In recent years, electronic image stabilization has been widely used in which image stabilization is performed by displacing the position of a cropping area (area to be displayed as an image) in picked-up image data, depending on detected camera shake. In performing this type of electronic image stabilization, the picked-up image data include the cropping area and a marginal zone (hereinafter, referred to as a buffer zone) for the cropping area when moved.
For example, Japanese Patent Application Laid-open No. 7-123317 discloses an image pickup apparatus having a vibration-reduction-function. The image pickup apparatus having the vibration-reduction-function displaces the position of an image read out from the field memory, depending on the amount of movement of image information between frames. With this arrangement, the image pickup apparatus having the vibration-reduction-function reduces the blur of the read-out image.
However, since the size of the picked-up image data cannot be changed, the size of the cropping area affects the image stabilization and the resolution in such electronic image stabilization as described above. When the cropping area is large, the high resolution in the cropping area is realized; however, the buffer zone is made to be small, whereby it is difficult to secure an amount of camera-shake-correction. On the other hand, when the cropping area is small, the buffer zone is wide, and the amount of camera-shake-correction is secured; however, the resolution in the cropping area is decreased. As described above, there is a problem that it is difficult to set a size of the cropping area since a required size of cropping area depends on image pickup conditions.